The present invention relates to a semiconductor device having a positive photosensitive resin composition of high sensitivity, capable of giving a pattern of high residual film ratio and provided with a bump electrode.
In conventional semiconductor chips, an inorganic film (e.g. SiO2 film or SiN film) is formed for circuit protection. Further, a polyimide resin is coated for relaxation of the physical damage given in the encapsulation step (e.g. transfer molding). Also, in recent years, in connection with the increase in the input terminals of a semiconductor chip, there has come to be employed flip chip mounting which comprises forming a bump on a bare chip and mounting the resulting chip on a substrate with the face directed down.
When, in the above semiconductor chip structure, bare chip mounting typified by flip chip mounting is employed, however, there has been a problem that the high water absorption of the polyimide resin incurs deterioration of dielectric strength and reduction in reliability, with the lapse of time.
There has also been a problem that the formation of polyimide pattern requires a long operational time and moreover is inferior in precision of processing.
The present invention aims at alleviating the above-mentioned operational problem in production of a flip chip and providing a semiconductor device superior in various reliabilities.
The present invention lies in a semiconductor device comprising:
(a) a polybenzoxazole resin film for chip protection, obtained by coating, on a circuit-formed chip, a positive photosensitive resin composition comprising 100 parts by weight of a polyamide represented by the following general formula (1) and 1 to 100 parts by weight of a photosensitive diazoquinone compound, and subjecting the coated composition to patterning and curing, and
(b) a bump electrode: 
wherein X is a tetravalent aromatic group; Y is a bivalent aromatic group; Z is 
(R1 and R2 are each a bivalent organic group, and R3 and R4 are each a monovalent organic group); E is a carboxyl aliphatic, alicyclic or aromatic group having at least one alkenyl or alkinyl group; and a and b are each a molar fraction, a+b=100 mole %, a=60.0 to 100.0 mole % and b=0 to 40.0 mole %; and n=2 to 500.
Preferably, the positive photosensitive resin composition contains a bisphenol compound represented by the following general formula (2) and a trisphenol compound represented by the following general formula (3) in a total amount of 1 to 30 parts by weight: 
wherein R5 and R6 are each a hydrogen atom or an alkyl group; R7, R8, R9 and R10 are each one atom or group selected from hydrogen atom, a halogen atom, hydroxyl group, an alkoxy group, a cycloalkyl group and an alkyl group, and 
wherein R11 is hydrogen atom or an alkyl group; and R12, R13, R14, R15, R16 and R17 are each one atom or group selected from hydrogen atom, a halogen atom, hydroxyl group, an alkyl group, an alkoxy group and a cycloalkyl group.
Preferably, the proportions of the bisphenol compound and the trisphenol compound are 10:90 to 90:10. The X of the polyamide is selected from the followings: 
The Y of the polyamide is selected from the followings: 
wherein A is xe2x80x94CH2xe2x80x94, xe2x80x94C(CH3)2xe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94NHCOxe2x80x94 or xe2x80x94C(CF3)2xe2x80x94. The positive photosensitive resin composition is cured at a temperature of 280 to 440xc2x0 C.